October 21,1937. Flight out of Tucuman along Calchaqui Valley, over Salto, and return. Head of Calchaqui valley: Panoramic view beginning W or N and continuing counter-clockwise. No. 16 and 17 look down the Calchaqui valley. The juncture of the horizon peaks is good but joining fails for the foreground areas because of rapid drift of the aircraft in the high wind at this altitude. 20000 feet. 08:10.